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, În urm? atoarele capitole voi prezenta nucleul acestei lucr? ari si anume studiul productiei de bosoni Higgs asociat? a cu perechea top quark, asa-numita productie ttH, în cadrul modelului standard si dincolo de acesta. Observarea productiei ttH cu detectorul ATLAS anuntata recent în 2018 reprezint? a o mare realizare, semnificativ? a pentru domeniul fizicii la energii înalte. Pentru a l? argi spectrul dincolo de SM, acest canal 4L a fost studiat, de asemenea, în contextul c? aut? arii unui boson dublu Higgs (H ±± ) ce de dezintegreaza în W ± W ±. În concluzii, voi face un rezumat al analizelor prezentate si voi prezenta o scurta perspectiva în cadrul, Al treilea capitol prezinta performanta calorimetrului electromagnetic, si anume studiul eficientei de identificare a electronilor folosind dezintegrarea W în electroni si neutrini

, Le travail scientifique présenté dans cette thèse s'appuie sur des collisions proton proton, à 13 TeV dans le centre de masse, produite par le grand collisionneur de Hadron (LHC) et enregistrées entre, 2015.

, Après une brève introduction sur le programme de physique du LHC, le premier chapitre donne un aperçu complet du contexte et des motivations théorique, Ensuite une description complète du détecteur ATLAS et plus généralement de l'ensemble expérimental est donnée en détaillant les différents objets physiques utilisés dans cette recherche

, Le troisième chapitre traite d'une des mesures des performances du calorimètre électromagnétique ATLAS, à savoir l'étude des efficacités identification électronique à l'aide de W se désintégrant en électrons et neutrinos

. Dans-les-chapitres-suivants and . Le-coeur-de-cette-thèse, la recherche et l'étude de la production associée de boson de Higgs avec une paire de quark top, appelée production ttH, est traitée dans le schéma du modèle Standard et au-delà. L'observation de la production ttH avec le détecteur ATLAS a été récemment annoncée en, 2018.

W. and H. ±±-?-w-±-w-±, cet état final du canal 4L a aussi été étudié dans le cadre de la recherche de bosons de Higgs doublement chargés se désintégrant en, En conclusions, les perspectives sur les futurs résultats scientifiques dans le modèle Standard (SM) ainsi que au-delà de SM (BSM) qui pourraient être atteint en utilisant les statistiques complètes des Run1 et Run2 combinés sont donnés